• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.525-529
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• 2022

In the eLoran system, the Loran Data Channel (LDC) is used to provide precise timing and positioning. The LDC message can be modulated with the Eurofix method, which modulates the transmission time of the 3rd-8th pulse not used for navigation, and the 9th pulse method, which modulates data using the 9th additional pulse after the existing 8 Loran pulses. In this paper, we analyzed the reception performance of the LDC message transmitted from the eLoran transmitter according to the modulation method. The eLoran testbed transmitter in Incheon was set to transmit LDC messages simultaneously with the 9th pulse modulation method and the Eurofix modulation method. Then, the LDC messages stored in the databases of the eLoran differential stations in Incheon and Pyeongtaek were analyzed in terms of the message reception rate according to the modulation method. Using the navigation aid management ship Inseong No. 1, the range of LDC message reception of actual sea users near Incheon Port was also analyzed. The results of this study are expected to be utilized in the full operational capability service after the eLoran pilot service.

• Journal of the Korean Institute of Navigation
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• v.17 no.1
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• pp.79-90
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• 1993

As the trend of ship's automation has spreaded over from 1950's , it caused shipping industries to develop new concept of ship's officer to operate new type of ships with high technologies. As a result, French started the education of Dual Purpose Officer (DPO) from 1967 for mariners who has skills and knowledge in navigation and engineering area. these experiments were concerned mainly with an improved carrier structure for officers, efficiency in ship's operation and subsequent cost saving, and in these years, many advanced countries in shipping business have been interested in the DPO system and adopted it especially in the Northern Europe and Japan. In Jorea there were researches for DPO based on experience of those in foreign countries in the middle of 1980's and established it with revision of relevant domestic regulation in 1990. Korean shipping industry will meet first graduates from DPO program in the near future but it seems that there were not sufficient studies to prepare actual practice. In the paper it was tried to analyze korean DPO system in the structure of education and certification by comparing them with foreign one and found that curriculums of the two maritime universites in Korea are quite suitable under circumstances of domestic shiping industry but some amendments are needed in relevant regulations.

• The Journal of Fisheries Business Administration
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• v.46 no.3
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• pp.15-29
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• 2015

The illegal, unreported and unregulated fishing can be properly regulated only if fishing activities, transhipment and landing of illegally caught fish, and processing of fish at sea involved in it are integrally managed. To do this, flag States, port States, coastal States, market States and relevant regional fisheries management organizations shall closely cooperate. In addition, fishing boats involved in IUU fishing often ignore requirements of safety of navigation so that they could be exposed to more causes of incidents and could have less chances to be rescued. Then, it seems to be necessary for the regulation on IUU fishing to include a certain consideration of strengthening safety of those ships. International Maritime Organization(IMO) has developed and implemented international rules for the safety of shipping. IMO has cooperated with Food and Agricultural Organization on IUU fishing since 2000 and the third joint meeting is scheduled in November 2015. This paper reviews the recommendations adopted in the previous meetings, and the measures actually taken as a result of the cooperation and, in particular, focus on the additional roles of IMO for the eradication of the IUU fishing.

• Journal of the Korean Institute of Navigation
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• v.19 no.4
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• pp.9-40
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• 1995

Since Korean Seamen Act(herein after called "the Act") has been legislated in 1962, an amendment of the Act has duly performed several times in order to meet an essential guideline of appropriate international convention and practical requirement of domestic labour movement. As the Act in many area, is based on the application of international convention and regulations, it has been considered essential to call attention to such international rules, to emphasize their importance, and to indicate how and to what extent they may be incorporated in national law, in accordance with national constitutional rules and requirements. Of newly amended act in 1991, it could, however, not fully reflect an adequate and modern labour standard as a guideline of the convention. Therefore, a principal objective of this paper is to provide a comprehensive reference work to assist amending up-to-data seamen act against the Act. The guidelines, however, do not attempt to suggest or formulate a legislative programme, but rather provide an ordered and specific content corresponding to international convention adopted by ILO. Consequentially, these guidelines aim to direct the reader and legislator toward the sources and contents of what has come to constitute an international code of maritime labour standards. The guidelines described herein may also serve as a specific arrangement to the various kinds of legal aspects to be regulated through reasonable future amendment under amicable agreement between interesting parties.g parties.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.47-56
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• 2015

Under the conditions of invested actual changes of heeling angles during MV Sewol's sinking, this study proposes passengers' evacuation scenarios, which are based on the assumption of normal orders of evacuation being given to the passengers, and evaluates using a marine-specialized human evacuation simulation tool. As results, when the heeling angle is set as 0 degree or 30 degree, it is found out that almost every passengers can success to evacuate to the musterstations, even though the evacuation times are different depending on the scenarios and the walking speeds. Meanwhile, when the heeling angle is varied as the Sewol incident, 3.1 %(Scenario Sc-Va which set chutes on port side as evacuation routes), 11.1 %(Sc-Vb, every open decks of port side as evacuation routes) and 20.0 %(Sc-Vc, every open decks of port and AFT sides as evacuation routes) among 476 passengers can successfully reach to the musterstations from their cabins with the condition of average walking speed as 2.04 m/s on flat. And only 0.8 %(Sc-Va), 3.8 %(Sc-Vb) and 10.7 %(Sc-Vc) can success to evacuate with the condition of average walking speed as 1.48 m/s on flat.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.43-60
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• 2010

The purpose of this paper is to show the clustering measurement way for Korean container terminals by using neural network based SOM(Self Organizing Map). Inputs[Number of Employee, Quay Length, Container Terminal Area, Number of Gantry Crane], and output[TEU] are used for 3 years(2002,2003, and 2004) for 8 Korean container terminals by applying both DEA and SOM models. Empirical main results are as follows: First, the result of DEA analysis shows the possibility for clustering among the terminals and reference terminals except Gamcheon and Gwangyang terminals because of the locational closeness. Second, the result of neural network based SOM clustering analysis shows the positive clustering in clustering positions 1, 2, 3, 4, and 5. Third, the results between SOM clustering and DEA clustering show the matching ratio about 67%. The main policy implication based on the findings of this study is that the port policy planner of Ministry of Land, Transport and Maritime Affairs in Korea should introduce the clustering measurement way for the Korean container terminals using neural network based SOM with DEA models for clustering Korean ports and terminals.

• Journal of Korea Port Economic Association
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• v.26 no.4
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• pp.63-87
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• 2010

The purpose of this paper is to measure the efficiency of Korean container terminals by using SFA(Stochastic Frontier Analysis). Inputs[Number of Employee, Quay Length, Container Terminal Area, Number of Gantry Crane], and output[TEU] are used for 3 years(2002,2003, and 2004) for 8 Korean container terminals by applying both SFA and DEA models. Empirical main results are as follows: First, Null hypothesis that technical inefficiency is not existed is rejected and in the trasnslog model, the estimate is significant. Second, time-series models show the significant results. Third, average technical efficiency of Korean container terminals are 73.49% in Cobb-Douglas model, and 79.04% in translog model. Fourth, to enhance the technical efficiency, Korean container terminals should increase the handling amount of TEUs. Fifth, both SFA and DEA models have the high Spearman ranking of correlation coefficients(84.45%). The main policy implication based on the findings of this study is that the manager of port investment and management of Ministry of Land, Transport and Maritime Affairs in Korea should introduce the SFA with DEA models for measuring the efficiency of Korean ports and terminals.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.496-505
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• 2020

In the previous research, the effectiveness of resonator was confirmed through the numerical analysis on two cases with the use of existing resonator at the Mukho and Imwon ports located in the eastern coast of South Korea by discussing the reduction rates of 1983 Central East Sea tsunami, and 1993 Hokkaido Southwest off tsunami, respectively. In this study, the reduction rates of tsunami height with three different resonators, Type I, II-1, and II-2, at the Samcheok port were examined respectively through the numerical analysis using COMCOT model under the same condition as the previous study. It was discussed the spatial distribution of maximum height of tsunami, change of water level, and effectiveness of resonator with the presence of new types of resonator, and change of their sizes. As a result, the effectiveness of resonator was verified through the application of new types of resonator reducing about maximum 40% of tsunami height. In order to design the optimal resonator for the variety of site condition, it is necessary to research about the various cases applying different shape, arrangement, and size of resonator as further study.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.8
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• pp.698-703
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• 2016

Francis hydro turbines have been most widely used throughout the world because of their wide range of head and flow rate applications. In most applications, they are used for high heads and flow rates. Currently, Korea is developing technology for Francis hydro turbine design and manufacture. In order to understand the internal details of Francis hydro turbines further, a new Francis turbine model runner is designed and model internal flow characteristics are investigated. The specific speed of the Francis hydro turbine model runner is $Ns=200m-kW-min^{-1}$. The runner blade is designed successfully according to the port area and one-dimensional loss analysis. The best efficiency point of the Francis hydro turbine model achieves 90% at the design condition. CFD analysis yields a hill chart of the Francis hydro turbine model for use in predicting performance.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.2
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• pp.121-128
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• 2021

According to the increasing interest and demand for the Autonomous Surface Vessels (ASV), the autonomous navigation system is being developed such as obstacle detection, avoidance, and path planning. In general, autonomous navigation algorithm controls the ship by detecting the obstacles with various sensors and planning path for collision avoidance. This study aims to construct and prove autonomous algorithm with integrated various sensor using the Robot Operating System (ROS). In this study, the safety zone technique was used to avoid obstacles. The safety zone was selected by an algorithm to determine an obstacle-free area using 2D LiDAR. Then, drift angle of the ship was controlled by the propulsion difference of the port and starboard side that based on PID control. The algorithm performance was verified by participating in the 2020 Korea Autonomous BOAT (KABOAT).